blob: 48dc855e71b28d6906a2b20cba0ccb6e545efd5d [file] [log] [blame]
Joe Onorato1754d742016-11-21 17:51:35 -08001/*
2 * Copyright (C) 2016 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17#ifndef FD_BUFFER_H
18#define FD_BUFFER_H
19
Yi Jinc23fad22017-09-15 17:24:59 -070020#include <android/util/EncodedBuffer.h>
Joe Onorato1754d742016-11-21 17:51:35 -080021#include <utils/Errors.h>
22
Joe Onorato1754d742016-11-21 17:51:35 -080023using namespace android;
Yi Jinc23fad22017-09-15 17:24:59 -070024using namespace android::util;
Joe Onorato1754d742016-11-21 17:51:35 -080025using namespace std;
26
27/**
28 * Reads a file into a buffer, and then writes that data to an FdSet.
29 */
30class FdBuffer
31{
32public:
33 FdBuffer();
34 ~FdBuffer();
35
36 /**
37 * Read the data until the timeout is hit or we hit eof.
38 * Returns NO_ERROR if there were no errors or if we timed out.
39 * Will mark the file O_NONBLOCK.
40 */
41 status_t read(int fd, int64_t timeoutMs);
42
43 /**
Yi Jin0a3406f2017-06-22 19:23:11 -070044 * Read processed results by streaming data to a parsing process, e.g. incident helper.
45 * The parsing process provides IO fds which are 'toFd' and 'fromFd'. The function
46 * reads original data in 'fd' and writes to parsing process through 'toFd', then it reads
47 * and stores the processed data from 'fromFd' in memory for later usage.
48 * This function behaves in a streaming fashion in order to save memory usage.
49 * Returns NO_ERROR if there were no errors or if we timed out.
Yi Jin0eb22342017-11-06 17:17:27 -080050 *
51 * Poll will return POLLERR if fd is from sysfs, handle this edge case.
Yi Jin0a3406f2017-06-22 19:23:11 -070052 */
Yi Jin0eb22342017-11-06 17:17:27 -080053 status_t readProcessedDataInStream(int fd, int toFd, int fromFd, int64_t timeoutMs, const bool isSysfs=false);
Yi Jin0a3406f2017-06-22 19:23:11 -070054
55 /**
Joe Onorato1754d742016-11-21 17:51:35 -080056 * Whether we timed out.
57 */
Yi Jin99c248f2017-08-25 18:11:58 -070058 bool timedOut() const { return mTimedOut; }
Joe Onorato1754d742016-11-21 17:51:35 -080059
60 /**
61 * If more than 4 MB is read, we truncate the data and return success.
62 * Downstream tools must handle truncated incident reports as best as possible
63 * anyway because they could be cut off for a lot of reasons and it's best
64 * to get as much useful information out of the system as possible. If this
65 * happens, truncated() will return true so it can be marked. If the data is
66 * exactly 4 MB, truncated is still set. Sorry.
67 */
Yi Jin99c248f2017-08-25 18:11:58 -070068 bool truncated() const { return mTruncated; }
Joe Onorato1754d742016-11-21 17:51:35 -080069
70 /**
71 * How much data was read.
72 */
Yi Jin99c248f2017-08-25 18:11:58 -070073 size_t size() const;
Joe Onorato1754d742016-11-21 17:51:35 -080074
75 /**
Joe Onorato1754d742016-11-21 17:51:35 -080076 * How long the read took in milliseconds.
77 */
Yi Jin99c248f2017-08-25 18:11:58 -070078 int64_t durationMs() const { return mFinishTime - mStartTime; }
Joe Onorato1754d742016-11-21 17:51:35 -080079
Yi Jin0ed9b682017-08-18 14:51:20 -070080 /**
Yi Jinc23fad22017-09-15 17:24:59 -070081 * Reader API for data stored in FdBuffer
Yi Jin0ed9b682017-08-18 14:51:20 -070082 */
Yi Jinc23fad22017-09-15 17:24:59 -070083 EncodedBuffer::iterator data() const;
Yi Jin0ed9b682017-08-18 14:51:20 -070084
Joe Onorato1754d742016-11-21 17:51:35 -080085private:
Yi Jinc23fad22017-09-15 17:24:59 -070086 EncodedBuffer mBuffer;
Joe Onorato1754d742016-11-21 17:51:35 -080087 int64_t mStartTime;
88 int64_t mFinishTime;
Joe Onorato1754d742016-11-21 17:51:35 -080089 bool mTimedOut;
90 bool mTruncated;
91};
92
Joe Onorato1754d742016-11-21 17:51:35 -080093#endif // FD_BUFFER_H